I know what you mean, I think it's because you expect the Vector to be more stable than it is, so you turn it over, and it burns. I thought it would be good for FH but a Zone or Rhyno is better for me. I decided I don't really have the power for the Vector, 300ft is Axis territory. I carry a 176 Axis as main mid and a 179 Axis in place of Vector. I enjoyed it a lot more new with a stable S flight before it broke in.

Also IMO like the Ion, vectors are very sensitive to OAT. If you do not throw these disc cleanly they will show turn but a good clean rip with a vector into 10-15 headwinds shouldn't turn it over as well as still have plenty of LSS fade.. The vector/ION have cleaned up my form a TON because the minute you are off, there they go to the right but if you release correctly they fly very stable. Its no zone or rhino but a vector that "turns and burns" is for sure not the disc.

I bought a black amp and found it to be just a tad bit understable, not nearly what I had expected. But after boiling-watering-down any dome and letting it sit under some books to flatten it out, it behaves almost exactly like it was described.

I'd see if you can reduce any domey-ness first before going out and buying another disc

Got an Anode for push putting recently because I wanted something understable and stiff to putt with. I'm loving it and have discovered throwing upshots and short to medium anhyzers with this thing works really well. Holds a perfect line with a lot of glide.

So, now I want some more MVP plastic but not sure what to get.

My drivers are Avengers, D4, and a recent River (which is pretty dead straight awesome).
My mids are Stalker, Buzzz and Fuse.
Putting with Anode. I was using a really beat in Wizard to putter driving and upshots but the Anode is taking over that spot.

So, what gaps am I missing that something from MVP could fill? I'm just so impressed with the Anode that I want to try some more but I don't want to redo my whole bag. The Stalker and the Buzzz are ones I really wouldn't mind replacing.

I would try the Axis if you're looking for a Buzz-like disc. I don't think that MVP makes a disc that would replace the Stalker. Keep in mind that the Axis does not handle OAT like a Buzz, so there will likely be an adjustment period. However, I find the Axis to be a bit more versatile than a Buzz once you get the hang of it.